Exchange silicate and method of preparing



Patented Se t. 12, 1 933 5 .is substantially neutral.

. EXCHANGE'YSILIOATE AND. ME

- PREPARING Harry MiltdKGray, Los Angeles, Calif., assignor 1 to H. Marks, Santa Barbara; Calif.

11g. Application March 3; 19

Serialf.No.{l32,'96 7 l.

No. Drawi cl ims. 01. ze-nelf and like'compounds, are made in a stronglyalkaline, molten magma, or solution and 'forthis reason, they produce softened water which is alkaline. 7 1- In the case of zeolite, the sodium contained in the zeolite is exchanged for the calcium and magnesium contained in the salts of thelatterwhich are inthe'hardwater. Thus calciumsul;

fate is transformed into sodium. sulfate. Sodium is the only element in thezeolites whichais ex-j, changed. This transfer of sodium' alonefrom-the water softening] material results in 'theisoftened water containing an excess of alkali.

I have found that byusing a water softening material which contains bothreplaceablesodium' and hydrogen that this difiicultycan' be .overcome I'nfother words, by using a material which is capable of transforming calcium sulfate, for

example, into sodium acid sulfate, the softened Sufficient acid isused so that the will .al-\

water will besub'stantially neutral and will re-, main so even when used in steam boilers- I obtain such an exchange silicate by slowly vaddingja solution of sodiumsilicate toajsolutionj containing an aluminum or'oth'er 'amphoteric metal sulphate, an acid and an oxidizing agent Ways remain acidic. Thisis of ital importance. I The sodium silicate is added only in sufiicient amount so that the silicate reaction product will contain not more thanhalf the total sodium which it is capable of holding. Due :to the mix being acidicand to the presence of the oxidizing agent,

the reaction product will then contain replaceable hydrogen as well as replaceable sodium.

Ordinarily I employ sulfuric acid to maintain the acidity of the mix and use nitric acid for the oxidizing agent. Examples of metal salts which can be used, in place of aluminum sulphate, are the sulfates of iron, chromium, zinc; nickel, copper and silver; I do not, however, intend to be restricted to the ingredients specifically set forth but intend to include all otherlike actingsub ing' material is the greater half gallons of water heit, for 2to 3 months. I

stances which would occur t6 those-skilled inthe' art. I

The method just outlined produces a silicate" gelQ-I prepare my final productfrom this' by thoroughly washing the-gel free of all waterj soluble substances which are present,pressing it into cakes and slowly drying it to produce a'rock likenon-pororis' material-which maythen be crushedand used for water softening purposes. Q

Among other advantages of my water soften- P. f

I flow rate, that canbe obtained by its use.-

The matter of making this compound in acid solution and in the presence ofan oxidizing agent, and adding exactly enough soda, only, is therefore, the essence of this, invention. To construct a compound that has'the cha'racteristicsjset forth I proceed in the following manner.

I takea 15 gallon jar or lead'lined-tankiand pour therein fifgallons of water; add one pound of aluminum or other amphoteric metallic sul- H 'phate which iss'oluble, stirwell and add 3 fluid I ounces of strong sulphuric acid, "and one ounce I,

of strong nitric acid. This is solution number 1 ThenI'take one half gallonofysilicate of soda, '1

40 deg. Baum gravity and addto'j'one and one lution number 2. V v r "Next, I add the two gallons "of number Zso- 1 lution, .tothe number lsolution 'in a 'fine stream with constant stirring and at a rate so that it willall be run together in two hours.- It is im-v and stir welLYThis is so- 'portantthatthe mixing is slowenough so that at all times the mix will be acidic, for if this condition is not'maintain'ed, the batch will be- 9 comespoiled." j The entire contents of the jar at once sets to a jelly like mass; after standing 2 hours I add 5 gallons of water. and stir, to break theijelly, up into small pieces or into a kind of 'batterrand let stand for6 hours.-

Then! I pour orsiphon off the clear liquid down to the jelly and fill'up with water again; 7 stir and let stand for 6 hours.

I again pour or siphon off the clear liquid down to the'jellyand fill up with Water, stir and let stand for 6 hours; After this third washing, which removes all soluble matter the jelly like mass is dipped out w or drawn off fromthe bottom into moulds and pressed for 3 hours tobricks or slabs. These are handled with great care, so asnot tov disturb the jelly formation, and set away to dry, at a temperature not to exceed 130 degrees Fahren- I V are ready jfor use.

and set to a hard glass like body or rock. These are crushed and screened to suitable size and To use this material; itis placed inra tank" or suitable containerand the water to be softened,

is allowed to pass through,'flowing in contact with the crystals. r r Now therefore, having fully described my invention, what lclaim as new, and desire to se;

{lure y Letters Patent isr- 1. The process of preparing a water softening sodium silicate to each pound git-aluminum sulfate, maintaining an acidic mix during said step,

3 allowing a gelgto form; thoroughly washing said material of the ..exchange silicate type, comprisgel to remove-all water solublegsubs'tances therea from, pressing the gel into cakes without dis-q turbing the .gel structure; and drying for a periodi of months at a temperature below 130? F.-

to produce a hard clos' e-grained non-porous m est 2- T V material .of the exchange silicate 7 type, which consists'in dissolvingl'an aluminumsalt in water containing sulfuric acid and nitric acid, slowly adding to the mixture a'solution of sodium sili-.- rate in amount insufficient to produce ;a silicate reaction product having more than half the possible sodium content, maintaining an acidic mix during said step, allowing a gel to form, thor oughly washing said gel to remove all water soluble substances therefrom, pressing the gel; into cakes without disturbing theigel structure} and slowly drying 'at af temperature-below 130. F. to.

a hard close-grained non-porous produce d t? 3. The process of preparing awater softening ing the steps of dissolving in vater containing sulfuric acid and nitric acid a salt of a'metal selectedirom.thevclass consisting of aluminum,

iron, chromium, zinc, nickelfcopper and silver,

slowly adding to the mixture a solution of sodium-silicate in amount insufipicie'nt to produce a vsilicate"reaction product having more "than an acidic mix during said step, allowinga gel to form, thoroughly washing. said gel to remove all water'soluble substances ther e i1-0n1,pressing the gel into cakes withoutl'disturbing the gel structure, and slowly drying, to produce a hard "zol :1

silicate type having a hard close-grained'nom I porous structure and having the property. of converting calcium sulfateinto sodium acidsulfate ing the steps of dissolvingan amphoteric-metal salt in water containing sulfuric acid and nitric acid, slowly adding to the mixture a solution of sodium silicate in amount insuiiicient to produce a silicate reaction product having more than half the possible sodiumcontent, maintaining an thoroughly washing the g'el'to remove all water soluble substances therefrom, pressing'the gel into cakes without disturbing-the gel structure,

and slowly drying to produce a hard closegrainedinon-porousYproduct;

"5.: In the process for preparing water softening material of'the' exchange silicatetype, the'steps comprising'reacting a solution of sodium silicate with an acidic solutionof; a water soluble ampho- :teric-metali'sulfate in the presence of an oxidiz ing agent typified by nitric acid, the proportions" being adjusted so as to maintain an acidic mix and so as to produce a silicate gel reaction prodacidic mix during said step; allowing a gel to form,

not having notmore than half the possiblesodium :content, washing the gel to remove watersoluble substances therefrom, pressing the gel into cakes and slowly drying. 1

6. In the process for preparing water softening ,7 material of the exchange silicate type, the step I of reacting a solutionof sodium silicate with an acidic solution of, a vwater soluble amphoteric- I, n r i 1 metal-salt in the presence of an oxidizing agent processof preparing a watersoftening typified by nitric, acid, the proportionsbeing adjusted so as to maintain an acidic-mix andso as to produce a silicategel reaction product having not more than half the-possible sodium content.

ioo

'7;-'A water softening material of the exchange when brought in contact witha solution of the former.

' s. "a waterso fteningmaterial ottheexchange silicate type having the propertyioi converting calcium sulfatef intosodium acid sulfate when brought incontact with a solution of the former.

T9,,A complex sodium hydrogen aluminum sili-, cate forusein'water softeningand having. the property of simultaneously exchanging, a sodium and a' hydrogen'atom for ja magnesium or cal ciun atom.

10. A water, softening material of the exchange silicate-type characterized by having'ani equal number of replaceable sodium, and hydrogen;

ll. A Water softening jmaterialof the exchange silicate" type characterized byfhaving' an equal atoms, 'wherebywater softened by itwillnot be v u v rendered alkaline. half the possible sodium content, 'maintaining number of replaceable sodiumi' and hydrogen atoms, by having alhard close-grained nonj porous structure, andb'y being capable of soften- 1mg water so; thatthe water will "not be alkaline iior'becgnnealkaline when used in steam boilers;

- TiIARnY' MILTONHCYIRAYL 

